Various polymerizable compounds can be prepared by reaction of lithium carborane with a bromocompound containing ethylenic unsaturation (U.S. Pat. No. 3,669,993, column 2, lines 1 to 15), or by a Grignard type reaction involving a bromoalkylcarborane and an alkenylbromide (U.S. Pat. No. 3,431,234). In the latter case, the resulting carborane is further converted to a carboranylsilane which can be polymerized to a heat resistant polysiloxane resin.
Another type of polymer known to the art is made by polymerizing cyclic dihalophosphazenes and, for water resistance, substituting alkoxy or aryloxy groups for the halogens in the molecule (e.g., U.S. Pat. Nos. 3,370,020; 3,880,800; and 3,883,451). One of these cyclic dihalophosphazene compounds, N.sub.3 P.sub.3 F.sub.6, has given good yields of mixed fluorophenyl phosphazenes, N.sub.3 P.sub.3 F.sub.6-n.phi.n, when allowed to react with phenyl lithium, .phi.Li. In general, however, organolithium reagents have showed, upon reaction with cyclic phosphazenes, a tendency to yield ring-opened compounds instead of the expected alkylated or arylated derivatives.
The principal object of this invention is to synthesize new carborane-substituted cyclophosphazenes and to polymerize these compounds to heat-resistant polymers that are mainly inorganic in character.